SafeSend

SafeSend is a secure file transfer backend that lets users upload files and share time-limited download links. Files are stored in AWS S3 and shared via short-lived pre-signed URLs so the backend does not directly stream file data.

MVP Features

• Upload a file and generate a shareable link token
• Download via token with expiration and max-download limits
• Audit logging for download attempts (success/fail + reason)
• Authenticated users can view file metadata and revoke links

Tech Stack

• Java, Spring Boot (REST API)
• AWS S3 (object storage, pre-signed upload/download)
• PostgreSQL (metadata + audit logs)
• Docker (local dev)
• Swagger / OpenAPI (API docs)

Architecture (high level)

• Client requests an upload
• API creates a metadata record and returns a pre-signed S3 upload URL
• Client uploads directly to S3
• Client shares a token-based link
• Download requests validate token rules and return a pre-signed S3 download URL

API Endpoints (planned)

Auth

• POST /auth/register
• POST /auth/login

Files

• POST /files
  Creates a file record and returns a pre-signed upload URL + share token.
• GET /files/{token}
  Validates token rules and returns a pre-signed download URL.
• GET /files/{id}/metadata
  Returns file metadata (owner-only).
• POST /files/{id}/revoke
  Revokes an existing share token (owner-only).

Local Development

Coming soon.

Demo

Coming soon.

Roadmap

• Add rate limiting
• Add background cleanup for expired files
• Add optional malware scan hook / scan status field